-Mountain castle looked down on valley of turbulent history-

Overview

Brief History

Mitake castle (三岳城) is located at the top of Mitakeyama mountain, one of about 400 meter height from hillside at the northeast of Iinoya valley. Mitakeyama mountain is a beautifully shaped one consist of three peaks, and as it places at the south edge of mountainous area in the central part of Honshu mainland, from its peak a spectacular view of southward from Lake Hamanako to Hamamatsu city is seen.Iinoya valley is a small and quiet valley of about 2 kilometer square formed by Iinoya-gawa river at the north of Lake Hamanako, a large lake at the western part of current Shizuoka prefecture. But the valley itself is an important point of communication where is a crossing point of east and westward road from Futamata area to Mikkabi area and north and southward road from Nagashino area to central Hamamatsu area, which still remain as Route 257 and Route 352. Because of this geographical condition, Mitake castle and Iinoya valley had been involved into many conflicts.

Origin of Mitake castle

Precise year is unknown but it is said that Mitake castle was built in 1336 by local lord Ii clan, probably utilizing existing mountain temple. Normally Ii clan lived at Iinoya castle at hillside, and used Mitake castle as a wartime fortress. The origin of Ii clan is also unidentified, but could be a descendant of central noble Fujiwara clan. Since 10th century Ii clan might grow their power as a local administrative staff of central government. At the battle of Hogen occurred between Retired Emperor Sutoku (1119-1164) and Emperor Goshirakawa (1127-1192), it is recorded that Ii clan belonged to Yoshitomo Minamoto (1123-1160) along with other local lords of Totomi province (western part of Shizuoka prefecture) such as Yokoji clan or Katsumata clan. When Yoritomo Minamoto (1147-1199), son of Yoshitomo, established Kamakura Shogunate, Ii clan served as a retainer of Shogunate and spread their territory around Lake Hamanako.In 1333, Kamakura Shogunate was ruined by Emperor Godaigo (1288-1339) and direct governance of Emperor started. But Takauji Ashikaga (1305-1358) who was a high class retainer of Kamakura Shogunate but changed to Emperor side, broke with Emperor then established his own Muromachi Shogunate. After the defeat at the battle of Minatogawa in 1336, Emperor Godaigo retreated to Yoshino area at the middle part of current Nara prefecture, opened South Court in opposing to North Court supported by Takauji Ashikaga.

Base of South Court

Under inferior situation, Emperor Godaigo sent his princes to different areas to gather local lords and resist to Muromachi Shogunate. In 1338, Prince Muneyoshi (1311-1385) who tried to sail to Tohoku region but met a shipwreck then landed to Totomi province (western part of Shizuoka prefecture). Prince Muneyoshi asked assistance to Ii clan, then Ii clan raised their army against Muromachi Shogunate then besiege at Mitake castle.In 1339, Iinoya valley was assaulted by dominant army of Muromachi Shogunate lead by Moroyasu Kou (?-1351) and Yoshinaga Nikki (?-1376). Shogunate army at first fell branch castles of Mitake castle such as Sentogamine castle or Kamoe castle, and next year finally fell Mitake castle. Prince Muneyoshi moved to Shinano province (Nagano prefecture) and kept his resistance over several decades, but after that Ii clan turned to Muromachi Shogunate.

Conflict with Imagawa clan

However, under Muromachi Shogunate, Totomi province became the target of struggle between Shiba clan and Imagawa clan, both were strong retainers of Shogunate. Once Shiba clan became the governor of Totomi province in the middle of 15th century, but at the end of this century Imagawa clan started to intrude into Totomi province and beat local lords such as Yokoji clan and Katsumata clan. In response to this, Yoshitatsu Shiba (?-?) who was the main family of Shiba clan and governor of Owari province (western part of Aichi prefecture) intruded into Totomi province to recover from Imagawa clan. Ii clan belonged to Shiba clan and fought against Imagawa clan over three years, but finally Mitake castle was fell by Imagawa clan in 1513. Ii clan surrendered to Imagawa clan and became their retainer.Imagawa clan which seized Totomi province grew into a strong warlord under Yoshimoto Imagawa (1519-1560). Yoshimoto next aimed to expand into Mikawa province (eastern part of Aichi prefecture), and as Ii clan resided at the border to Mikawa province (eastern part of Aichi prefecture, Ii clan had to work had as a vanguard of Imagawa clan. Around this time, Ii clan lost successors in the battle or punishment by Imagawa clan.

Turbulence of Totomi province

Furthermore, in 1560, Yoshimoto Imagawa intruded into Owari province held by Nobunaga Oda (1534-1582) died in the battle of Okehazama by sudden attack of Nobunaga. Ii clan lost their leader Naomori Ii (?-1560), and Naochika Ii (1535-1562) who lost his father by Yoshimoto Imagawa succeeded Ii clan.However, Ujizane Imagawa (1538-1615), the successor of Yoshimoto Imagawa, could not manage local lords well. and Motoyasu Matsudaira (1543-1616, later Ieyasu Tokugawa) who was the lord of Okazaki castle (Aichi prefecture) and subordinated to Yoshimoto left Imagawa clan and seized Mikawa province.Under such situation, local lords of Totomi province wavered between Ujizane Imagawa and Ieyasu Tokugawa. Ieyasu urged secession of local lords of Totomi province including Iio clan at Hikuma castle (later Hamamatsu castle), Amano clan at Inui castle and Ii clan, then Ujizane became dubious for loyalty of these local lords.

Loss of successors

In 1562, hearing a plan of betrayal of Ii clan, Ujizane Imagawa called Naomori Ii to his capital Sunpu city for explanation. But on the way Naomori was killed by Asahina clan which was the important retainer of Imagawa clan, and Naohira Ii (1478-1563) who was the grandfather of Naomori and still survived also died in ill soon. This time Ii clan lost all successor except for Naomasa Ii (1561-1602) who was still two years old infant.At this time, Naotora Ii (?-1582) who was a cousin of Naochika Ii and only survived elder people of Ii clan became the female lord. To avoid assassination or hostage Naotora hided Naomasa Ii at Horaiji temple of Mikawa province, and exercised her power as a woman priest of Ryotanji temple, a family temple of Ii clan. But at this time Mitake castle was deprived by Imagawa clan, and Naotora herself was sometimes expelled from Iinoya valley. Around this time Ujizane Imagawa reformed Mitake castle along with neighbor castles such as Uzuyama castle or Sentogamine castle as a front line against Ieyasu Tokugawa at westward. Mitake castle roughly consist of central area at the peak, secondary area at eastern ridge and third area existed at the halfway.

Structure of Mitake castle

Central area of Mitake castle is a round shaped area of 50 meter diameter, which consist of several layer of terraces. As its western slope is connected to gentle ridge, this slope is securely protected by layer of terraces which is protected by clay wall over 150 meter long. This clay wall is partially strengthened by stone masonry built by small stones, especially for entrance and upward path. This structure quite resembles to the one at Uzuyama castle, which might be also reformed under Ujizane Imagawa.Secondary area at eastern ridge is a simple flat area over 200 meter long might be used as a camping place or storage. Unlike central area there is no clear defense facility, but its eastern edge is also protected by layer of terrace and dry moat. At its eastern and western edge, line of stones still remains which might work as a path to the entrance. Third area at the halfway which is used as a ground of shrine might be used as a water source of the castle with a well. It is said that the palace of Prince Muneyoshi existed at this place. Total size of Mitake castle exceeds 400 meter long, and considering its size and location at steep mountain it is wonder why this castle fell easily several times.

Female lord Naotora Ii

Ujizane Imagawa struggled to hold Imagawa clan, and Naotora Ii also barely kept Ii clan in conflict with Imagawa clan. But in 1568, Shingen Takeda (1521-1573), the warlord of Kai province (Yamanashi prefecture) and former ally of Imagawa clan, broke the treaty and invaded into Imagawa territory in cooperation with Ieyasu Tokugawa. Tokugawa clan once captured Totomi province, but next to face the pressure of Shingen Takeda. In 1572 Shingen Takeda started his campaign against Ieyasu Tokugawa and his ally Nobunaga Oda, then intruded into Totomi province and broke Tokugawa army at the battle of Mikatagahara. At this time Takeda clan intruded into Iinoya valley then Mitake castle might be captured Takeda clan. However, on the way of campaign, Shingen died in ill in 1573. Two years later Nobunaga Oda and Ieyasu Tokugawa broke Katsuyori Takeda (1546-1582), the successor of Shingen Takeda, at the battle of Nagashino, then pushed out Takeda army from western part of Totomi province. As the situation became stabilized, Naotora Ii urged Naomasa Ii to serve to Ieyasu, then Naomasa became the page of Ieyasu.

Revival of Ii clan and afterward of castle

Under Ieyasu, Naomasa activated both at battle and politics then rapidly promoted to general, and also held Iinoya valley as the lord. After the ruin of Takeda clan, the elite troop of Takeda clan was attached to Naomasa, and feared as the red colored army of Ii clan. In 1590 Ieyasu Tokugawa was transferred to Kanto region by Toyotomi government, then Naomasa Ii also moved from Iinoya valley then Mitake castle might be abolished at this time.Later Naomasa promoted to the first positioned retainer of Tokugawa clan and served as the commander of important castles such as Minowa castle, Takasaki castle (Gunma castle), Sawayama castle and Hikone castle (Shiga prefecture). Under the patience of female lord Naotora Ii and talent of Naomasa Ii, Ii clan which was forced to the corner of disappearance leaped to the first positioned general of Edo Shogunate. Now all building was lost but structure of the castle still remain on the mountain. Overall impression of primitive 14th century style and partial reform of western end shows long term use of Mitake castle. This also reflects long term turbulent history of Ii clan and Iinoya valley, being surrounded by strong powers and affected by various events. Prominent view from central area might encourage people of Ii clan even though in tough situation.